/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing.testers;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.AbstractCollectionTester;
import com.google.common.collect.testing.Helpers;

import java.util.Collection;
import java.util.List;

import org.junit.Ignore;

/**
 * Base class for list testers.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class AbstractListTester<E> extends AbstractCollectionTester<E>
{
    /*
     * Previously we had a field named list that was initialized to the value of
     * collection in setUp(), but that caused problems when a tester changed the
     * value of list or collection but not both.
     */
    protected final List<E> getList()
    {
        return (List<E>) collection;
    }

    /**
     * {@inheritDoc}
     *
     * <p>The {@code AbstractListTester} implementation overrides {@link
     * AbstractCollectionTester#expectContents(Collection)} to verify that the order of the elements
     * in the list under test matches what is expected.
     */
    @Override
    protected void expectContents(Collection<E> expectedCollection)
    {
        List<E> expectedList = Helpers.copyToList(expectedCollection);
        // Avoid expectEquals() here to delay reason manufacture until necessary.
        if (getList().size() != expectedList.size())
        {
            fail("size mismatch: " + reportContext(expectedList));
        }
        for (int i = 0; i < expectedList.size(); i++)
        {
            E expected = expectedList.get(i);
            E actual = getList().get(i);
            if (expected != actual && (expected == null || !expected.equals(actual)))
            {
                fail("mismatch at index " + i + ": " + reportContext(expectedList));
            }
        }
    }

    /**
     * Used to delay string formatting until actually required, as it otherwise shows up in the test
     * execution profile when running an extremely large numbers of tests.
     */
    private String reportContext(List<E> expected)
    {
        return Platform.format(
                "expected collection %s; actual collection %s", expected, this.collection);
    }
}
